At first, referring to FIGS. 7 and 8, the structure of a surface treatment device which is comprised of the board unloading device will be described as follows. FIG. 7 shows plane view of the surface treatment device 100 from upside. FIG. 8 shows side view of the surface treatment device 100 from α-direction.
FIGS. 7 and 8 shows the plating device of so-called pusher type as the surface treatment device 100, and having such that the transport hanger 15 which is holding the board such as a printed board, rise-and-fall guide rails 10, 12 which rise and fall with the slidable transport hanger 15, and fixed guide rails 11, 13 which transport the transport hangers 15 sequentially while keeping each predetermined space of backward and forward.
As shown in FIG. 7, pre-treatment tank 1 of each type for processing before plating, plating tank 2 for electroplating, recovery tank 3 and water-washing tank 4 for processing after plating, unload section 5 that is arranged the board unloading device for unloading a board, exfoliate tank 6 for separating plating films, water-washing tank 7 for water-washing the transport hanger 15 after separating, and load section 8 for loading a board, are arranged along these guide rails 10-13.
Rise-and-fall guide rails 10, 12 shown in FIG. 7 are guide rails which rise and fall when loading or unloading the board W (such as printed board), and when dipping the board W into various type of tanks (e.g., plating tank 2, exfoliate tank 6, water-washing tank, and hot water-washing tank). Fixed guide rails 11, 13 are guide rails respectively for transporting the transport hanger 15 which has fallen into plating tank 2, exfoliate tank 6, etc. When Rise-and-fall guide rails 10, 12 has fallen as shown in FIG. 8, guide rails 10-14 configure one circular guide rail.
Referring to FIG. 9 and FIG. 10, the structure of conventional transport hanger 15 transported by the surface treatment device 100 will be described as follows. FIG. 9 shows detail structure of the transport hanger 15. FIG. 10 shows partial cross-section near the center of the transport hanger 15.
As shown in FIG. 9, the transport hanger 15 has treating-object holding member 90 with plural clamps 48 for holding the treating-object W, slide member 35 which contact sidably with guide rails such as fixed guide rail 11, and connecting members 44 for connecting such members.
As shown in FIG. 9, the treating-object holding member 90 has horizontal rods 46 which are continuously connected with the connecting member 44 and extended to nearly-horizontal in transporting direction, plural drooping rods 49 which are placed on the predetermined position of the horizontal rod 46, and clamp 48 which clamps the board on lower end of the drooping rod 49.
As shown in FIG. 10, the clamp 48 is comprised of fixed part 48a and movable part 48b. The movable part 48b is rotatably attached to the axis of the fixed part 48a. The clamp 48 is activated by a spring to close tip end of the fixed part 48a and the movable part 48b in normal condition. As the clearance is made on tip of the fixed part 48a and the movable part 48b by pressing the top edge of movable part 48b against spring force, therefore it becomes possible to insert the board W into the clearance.
The board unloading device 5′ placed in unload section 5 is, as shown in FIG. 1l, comprised of a clamp opener 50, a hanger supporter 51, and a container 53.
The clamp opener 50 is configured by attaching a clamp press member on tip of a press cylinder, and when the transport hanger 15 of FIG. 7 arrived above the unload section 5 has fallen with Rise-and-fall guide rails 12 as shown in FIG. 11, the press cylinder of the clamp opener 50 is activated to unlock clamping by expanding and pressing the top edge of movable part 48b of clamp 48 (FIG. 10). The hanger supporter 51 is configured by attaching a support plate on tip of support cylinder, and supports the treating-object holding member 90 of the above-mentioned transport hanger 15 which has fallen, before activating the clamp opener 50, by activating the support cylinder to expand and contacting the support plate from the opposite side of the clamp opener 50. Therefore, it is possible to prevent from weakening the press force caused by bending the treating-object holding member 90 of the transport hanger 15. The container 53 is placed at downside of the transport hanger 15 fallen with rise-and-fall guide rail 12, further receives and houses the dropping board which is unlocked clamping.
The board unloading device 5′, which is comprised of the clamp opener 50 and the hanger supporter 51 and the container 53, activate the transport hanger 15 clamping the board W falling with Rise-and-fall guide rail 12 to drop into the container 53 when unlocking the clamp by a clamp opener 50 and a hanger supporter 51, and after that it will be carried and piled by worker (Refer to the Japanese Laid open Patent Application No. 2002-363796).
However, the above-mentioned conventional board unloading device 5′ has the following type of problems.
It was so troublesome and bothering task for worker to pile the board W dropped into the container 53 shown in FIG. 11. And, as surface tension occurred from treatment liquid sit on the surface of the board W and claggy plating made the board W not to separate from clamp 48 when unlocking clamp, it caused the device to stop operation in some cases. Furthermore, it occurred that the upper part of the board W (which is not adequately housed by the container 53) was bent when the board is thin such as below 0.1 mm thick, because the board W stuck to the container 53 while dropping by the above-mentioned surface tension.